The Sun is Back!

For those who suffer from seasonal affective disorder or a bit of dark-day low spirits, this is a special time of the year.   

Relief is on the way!  The sun is coming back...very quickly.

Consider the solar radiation reaching the surface in Seattle over the past year (below).  

It was pretty depressing near the turn of the year, with values consistently below 5 (megajoules per square meter, if you want to know the units).  But during the last few days we have received almost three times as much!

The length of day has also gotten longer...much longer, something shown graphically by the "Sun Graph" for Seattle (below)

This figure shows the length of day, with the light blue color indicating the period between morning and evening civil twilights.   We have gained several hours of light compared to the depth of winter and are now in the period when the length of day is increasing most rapidly.

Feels very good.

For a meteorologist like myself, the return of the sun has implications far beyond its pleasant feel on the skin.

The increasing solar radiation results in the warming of the surface, while the atmosphere above remains quite cool.

The result is that temperature change with height, the cooling with height, becomes very large this time of the year...and that has big implications.

A large temperature decline with height (also called a large lapse rate) results in the atmosphere becoming unstable and convecting, not unlike the situation in a lava lamp that is heated from below (see example below).

In the atmosphere, such instability leads to fields of cumulus clouds, such as shown below.

Today, large fields of sun-driven cumulus clouds were observed all over Washington State (below). 

 You see all the little white dots over land across the western side of the Olympic Peninsula?  Or the little white specks southwest of Spokane?  Lots of cumulus clouds.

 Blame the warming effects of the incipient sun of spring.

Will the Key Weather and Climate Facility in the United State be Sold Off?

 There are many media stories circulating today stating that the key U.S. weather and climate facility in the U.S. is going to be sold off:  The NOAA Center for Weather and Climate Prediction.

This location houses many of the key groups overseeing U.S. weather and climate prediction.  I have attended meetings in the facility or met with NOAA/NWS scientists there literally dozens of times.

Selling off this building and dispersing the groups housed there would be a death blow to US environmental prediction capabilities.

The question: Is there any truth to this?  Certainly, this story has been distributed through dozens of major and minor media outlets.   But as you know from my previous blogs, I am not a little cynical about the "facts" found in many media outlets--so let's check it out.

This story originated from two sources.  One is a story in Axios (see below).

The second was in The Verge, a technology website.

Neither of these websites can point to any official statement or documents to support these claims, just unnamed "sources."

I went to governmental websites, such as the DOGE lease cancelation list (see below).  No mention of the NOAA Prediction Center. None.

Checked the GSA website.  The NOAA facility is not on it.

The NOAA Prediction Center was a custom-built building designed for the important role it is now playing.  To sell it off would be a catastrophic error, with profound impacts on weather and climate prediction in the U.S.

There is no sign of any official intent to sell the building, and I suspect the stories noted above are not correct.

NOAA plays a crucial role in collecting weather and climate data,  ocean and atmospheric research, and predicting weather and ocean conditions.   Although essential, NOAA needs reform, particularly in dealing with an ineffective bureaucracy and loss of innovation.

When will DOGE and the new administration talk to the atmospheric and ocean community to learn about these problems and how to correct them?

With reform and rational change, U.S. weather and environmental prediction could be substantially improved.

A Very Wet California

 If you are wondering where much of our precipitation will be headed, look to the south.  California is going to be very wet during the next week or so.

Below is the predicted total precipitation through March 18, using the European Center model.  As much as 12 inches over portions of Northern CA.    Even LA gets fairly wet.

Seattle will be drier than LA...think about that.

Why is this happening?  

Because one after another, upper-level troughs of low pressure will plunge southward into California, leaving Washington State relatively high and dry.  Troughs are associated with upward motion and precipitation.

Let me show you a series of upper-level charts that present the heights of the 500 hPa pressure surface.  You can think of this as the pressure around 18,000 ft.  Blue and white colors indicate below-normal pressures...or troughs.

At 4 AM this morning, a trough was over southern CA.

Three days later (Thursday at 4 AM), another trough is over California.

Sunday night at 11 PM, ANOTHER trough is digging down over California.

Next Thursday morning at 11 AM, another trough is pushing into California.

You won't believe this.. on Friday night, one more trough moves into California.

This kind of pattern has dominated much of this winter.

Why?  As far as I know, there is no clear answer, but something is forcing this persistent troughing over the Golden State.

With all the troughing action over CA, reservoir levels are quite high throughout the state.   

But there is a major concern.  Substantial late winter precipitation leads to bountiful growth of chaparral vegetation, which can enhance the potential for wildfire later in the year.   The past few years have had wet winters, which contributed to the huge fires around Los Angeles.

UFO Clouds

 I received a half-dozen emails this week about some strange clouds visible on Wednesday. 

  A few asked (perhaps in jest) whether they were connected to UFOs or some paranormal phenomena.

Picture by James Robers

Picture by Kathleen Millen

They are not natural.  Something artificial caused these strange cloud holes.

Aircraft.

These features have several names:  hole-punch clouds, fallstreak holes, and punch hole clouds are some examples.

They are generally associated with a middle-level cloud deck, such as an altocumulus layer, in which the clouds are supercooled, which means liquid water clouds below freezing. 

 Typically, supercooled cloud water can occur when the air temperature is between 0C and -15C (32F to 5F).

Here is a satellite picture around the same time as the first picture was taken....you can see the extensive cloud layer.

It is fascinating that clouds can be made of liquid water that is below freezing.  

However, things can change fast if such a cloud deck is disturbed by an aircraft that is either ascending or descending through it. Such aircraft passages can cause some of the supercooled liquid water to freeze.  How?

One way is that the wings can cause pressure to fall, and that leads to cooling, cooling the air enough so that the water freezes.

Once one gets some ice, water vapor rapidly moves to the ice crystals causing them to grow and fall out.

This is a very fast process that quickly causes the liquid water droplets to evaporate and ice crystals to fall out.

A cloud hole is born!

You can often see the ice crystals falling out, and that is why they are called fallstreaks.

Don't like this explanation.  Don't worry....there is another one.....